Spectrum requirements for TV broadcast services using cellular transmitters

Abstract

Wide-spread provisioning of TV services has strongly shaped the cultural development since the last century; terrestrial radio broadcast transmission has been the original form of TV distribution. Although the majority of TV reception is today based on alternative distribution means, like cable or satellite, TV broadcast enjoys still a significant amount of allocated terrestrial spectrum (∼300 MHz). However, it has been identified that TV broadcast does not efficiently use its allocated spectrum. At the same time, other spectrum users like mobile communication systems experience a tremendous growth and demand for spectrum. The scarcity of radio spectrum has led the US FCC rule that additional 500 MHz of spectrum are to be identified for mobile broadband systems in the next decade — out of which 120 MHz are to come from the TV band in the next 5 years. In this paper we identify an alternative transmission architecture for TV distribution based on cellular LTE MBMS, with densely placed low-power transmitters that transmit in a synchronized single frequency network. It is demonstrated that in this way a full frequency reuse at all sites is possible, in contrast to the large reuse distances in high-power high-tower TV transmission. As a result, we show that it is possible to support TV services with 84 MHz of spectrum via LTE MBMS, in contrast to the 300 MHz used by today's ATSC TV broadcast system. This approach can be realized in a cost-effective manner by re-using existing mobile network infrastructure and we also show that the total radiated power can be decreased.